Informal Fallacies: Logical Side-shows

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There isn’t a fixed number of fallacies, and everyone is free to invent his own.  I will begin by inventing a fallacy to be called (drumroll!):  THE APPEAL TO FALLACIES.  It is a way of distracting attention from an opponent’s argument by calling attention to a fallacy.  Let’s see how it works.  The Governor is opposing tax increases, and is presenting arguments against them.  His opponents challenge him, pointing out that he favored tax increases fifteen years ago when he was little known in politics.  This is tu quoque (“You, too”—You have said it/done it yourself!), and it is a logical fallacy, since the fact that he took a different position in the past doesn’t mean that his present position is wrong.  You point that out, and defend him by asking why they descend to logical fallacies to attack him.  And you insist that trying to rake over ancient history is no way to solve today’s problems.  At the very least, you might change the focus of the discussion.  And who is in the right, here?  None of this tarradiddle is of any value in helping us find out.  As Schopenhauer says in The Art of Controversy, the safest way to win an argument is to be in the right from the beginning, but—given the weakness of the human intellect—it is not at all necessary.


The fallacies are a heterogeneous collection, and many attempts have been made to classify them systematically.  I have been guilty of a few, myself, but am now thoroughly repentant.  One old classification has three subcategories.  There are the formal fallacies, those in which the form of the argument is in question, and two types of informal fallacies:  material fallacies and verbal fallacies.  Material fallacies are those in which the assumptions underlying the argument—the material out of which it is made—present problems.  Verbal fallacies are those that rely on improper or ambiguous use of language for their effect.  This is a good start, but it leaves out an important category sometimes called psychological fallacies, those which appeal to emotional and other biases.


Before we can make much headway in dealing with fallacious arguments, we need to separate the formal from the informal fallacies.  (An argument is said to be fallacious if it is based on false premises, or is irrelevant or misleading.)  Formal fallacies—since they bear on the form of the argument, itself—should always be pointed out.  One example is the fallacy of the undistributed middle, which appears in the syllogistic argument “Some men are sports lovers, and all great athletes are sports lovers, so some men are great athletes.”  Both the premises and the conclusion are likely to be true, but no matter how reasonable this argument sounds, it is fallacious because the premises do not lead to the conclusion.  To see that this is so, we can substitute different terms into the same argument form, “peanut lovers” for “sports lovers” and “monkeys” for “great athletes.”  When we do this we get:  “some men are peanut lovers, and all monkeys are peanut lovers, so some men are monkeys.”  The premises sound as if they must be true, but the conclusion is clearly false.  There must be a problem with the argument’s form since true premises can never lead to a false conclusion if the argument is valid—that is the definition of validity.  This makes the undistributed middle a formal fallacy.


There is a very limited list of formal fallacies corresponding to the various formal argument structures.  Much more common are the informal fallacies: material, verbal, and psychologicalHasty generalization is an example of a material fallacy.  Suppose that someone is arguing that service dogs (such as dogs for the blind) present no problems to people with allergies if they are taken into restaurants or other enclosed spaces.  He knows three people with dog allergies and they only get contact dermatitis, so he argues that if people who are prone to allergies don’t touch service dogs, they will be fine.  This generalization from three cases to the whole population is made much, too hastily.  In fact, about 30% of asthmatics may be allergic to the dog’s dander, microscopic skin flakes that drift around in the air carrying allergens with it.  The material from which the argument is made includes the assumption that the presence of dog’s dander is not a serious problem, so it is faulty.  Material fallacies should be pointed out whenever we see them.

The verbal fallacies category includes equivocation.  Equivocation occurs when someone picks a meaning for a word that is different from the meaning another person is using, and bases an attack on that.  The most common example of equivocation may be the argument that evolution shouldn’t compel our belief because it is “just a theory,” that is, just a notion or idea.  We all know people who try to explain events by casually trotting out the word “theory”:  “Well, I’ve got a theory about that.”  This use is equivocal when it is applied to evolution because that is not what scientists mean by the word.  For them, a theory is a strongly verified general explanation for something.  This “strong verification” makes scientific theories matters of fact, not mere ideas.  If we are to have intelligent discussions, we have to understand the same thing by the words we use, so verbal fallacies should be pointed out whenever they are used.

Psychological fallacies are a different matter entirely.  This category includes the appeal to authority.  Suppose that a university professor belongs to a “think tank,” and his work is cited to support some argument.  The “think tank” may have a grandiose, patriotic name such as “The American Democracy Institute,” but it may be funded entirely by a special-interest group (this is very, very common).  The professor may have written many articles and even published a book or two, but it is possible that the majority of scholars believe his views to be wrong.  At a minimum, we should ask one important question:  what is this man’s standing in his field?  You will notice that this doesn’t bear on the material from which the argument is made or the language in which it is embodied.  And we may not need to oppose the argument at all if the source (the professor, here) is not reliable:  his lack of authority is what should be attacked.


Unfortunately, the system of categories we have been looking at isn’t adequate.  What do we make of the call for perfection?  The slogan “guns don’t kill people, people do,” is an example.  If we were to take this to heart we would have to change the behavior of people in order to reduce the number of gun deaths—as opposed to enacting gun-control laws.  It is obviously easier to try to change the laws than to change the morals or impulsive behavior of people.  (an appropriate response would be, “No, People with guns kill people”— it is clearly true, so it can’t be refuted, and it puts the argument back on course.)

The call for perfection has this name because it implies that we should be addressing the “root cause” rather than “putting a band-aid” on the problem.  It is sometimes classified as a psychological fallacy, but it is not at all clear what emotional bias it is supposed to appeal to.  It is related to the fallacy of pointing to another wrong.  Suppose someone is arguing that we need to spend money to improve fire protection, and someone else counters this by saying that the police need more money as well.  This may lead to a lively debate, but it doesn’t solve the fire-department’s problem, which is the issue under discussion.

To get around these problems we will add a catch-all category:  ignoratio elenchi (don’t you just love these names!).  Broadly speaking, this is the fallacy of irrelevance.  Whenever someone offers an argument that doesn’t deal with the point at issue he is guilty of ignoratio elenchi—of irrelevance.  We now have formal, material, verbal, psychological, and irrelevant as categories of fallacious argument.

The worst problem presented by the informal fallacies is the fact that they are often not fallacious at all.  Instead, they may be feeble arguments that lead to reasonable suspicion in some cases—though not to any kind of proof.  They are called fallacies only because they do not lead to certainty, although unscrupulous or ignorant people might present them as if they do.  For example, we can’t argue with any certainty that the governor is now wrong because he once thought differently, and we can’t argue that he is right because of that, either—though one would expect that a politician’s views might change as he gains more experience.  Thus, to oppose tax increases might now be seen as a responsible decision, but it is also true that politicians of the worst stripe might change their views to court votes.  To know what to make of this we would have to look at the circumstances surrounding their opinion in each case, but even that is a digression.  We don’t have to do anything at all.  We should simply stick to the point:  are there any good reasons to raise taxes now?

The important thing to do in any argument is to focus on the point at issue and to ignore all side-shows (as long as you don’t appear to be dodging them).  How important is it that the person presenting the argument seems stupid, or bigoted or ill-informed (ad hominem) if the argument itself is good?  How important is it that he threatens you (ad baculum) or appeals to your pity (ad misericordium) if the argument is bad?  How important is it that he wraps himself in the flag or appeals to traditional values (ad populum) if they are not relevant?  How important is it that he has movie stars on his side (ad verecundium) when they are not acknowledged experts?  How relevant is it that he attacks your examples rather than your argument or tries to shift attention to another problem when it is not the one under discussion (ignoratio elenchi)?  To keep the focus on the point at issue is hard:  but the ability to name fallacies is of little help when you are trying to defend yourself.  To answer irrelevant argument is to move away from the point that needs addressing.

All side-shows can be side-lined if one is careful not to dismiss their importance.  The governor can say, “I’ve changed my mind as a result of exploring all of the issues.  Let’s look at them carefully.”  All of the other informal fallacies can be addressed in a similar manner.  “I don’t believe he is a bigot, and the question is a red herring.  It doesn’t mean that this is bad legislation—let’s look at it.”  “Of course I value the spirit that made this country great, but that doesn’t mean that we shouldn’t act on this.  Why, exactly do you think that it won’t work.”  “Micky Mouse’s concern for the situation in the Middle-East was commendable, but experts who have spent years studying this problem do not agree with him.  Let’s try the case on its merits.”  “Perhaps I chose a bad example, but there are hundreds to choose from.  Let’s look at another.”  These statements all serve the purposes of civil discussion, but if you are not respectful, you give your opponents something to complain about, and that can be the biggest side-show of all.  You mustn’t say, “What difference does it make if he’s a bigot?” or “Patriotism is irrelevant, here!”  That is to commit suicide.

If you can keep your focus on the point at issue, the informal fallacies may all become irrelevancies and that is probably the best way to treat them.